/Engine/Source/Runtime/GeometryCore/Public/PlaneTypes.h
N = Cross(P1-P0,P2-P0)/Length(Cross(P1-P0,P2-P0)), c = Dot(N,P0) where P0, P1, P2 are points on the plane.
TPlane3 ( const [UE::Math::TVector](API\Runtime\Core\Math\TVector)< RealType > & P0, const [UE::Math::TVector](API\Runtime\Core\Math\TVector)< RealType > & P1, const [UE::Math::TVector](API\Runtime\Core\Math\TVector)< RealType > & P2 )